U.S. patent number 4,664,427 [Application Number 06/718,563] was granted by the patent office on 1987-05-12 for quick connect fitting.
This patent grant is currently assigned to Master Industries, Inc.. Invention is credited to Robert L. Johnston.
United States Patent |
4,664,427 |
Johnston |
May 12, 1987 |
Quick connect fitting
Abstract
A quick connect fitting for tubing which can be inserted into a
pre-assembled fitting where it will become sealed and locked
against pull-out. A main fitting body has an open-ended recess in
which is located a movable piston to seal against the body and an
inserted tube. The piston wedges over a conical extension on a
sealing gland retained by a snap-on cap, the gland and the cap
having complemental spherical surfaces to allow swivel movement of
the tube without disturbing the seal in the tube. A locking ring
retainer grabs the tube annularly and bears against the piston to
resist pull-out.
Inventors: |
Johnston; Robert L.
(Greenville, OH) |
Assignee: |
Master Industries, Inc.
(Ansonia, OH)
|
Family
ID: |
24886550 |
Appl.
No.: |
06/718,563 |
Filed: |
April 1, 1985 |
Current U.S.
Class: |
285/340; 285/270;
285/334.2; 285/902; 285/921 |
Current CPC
Class: |
F16L
37/52 (20130101); F16L 37/0927 (20190801); Y10S
285/921 (20130101); Y10S 285/902 (20130101) |
Current International
Class: |
F16L
37/00 (20060101); F16L 37/098 (20060101); F16L
37/52 (20060101); F16L 017/00 () |
Field of
Search: |
;285/231,232,261,266,178,270,271,340,341,334.2,334.3,DIG.3,DIG.22,223,342,343 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
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|
|
|
|
858049 |
|
Dec 1952 |
|
DE |
|
2750547 |
|
Sep 1978 |
|
DE |
|
912514 |
|
Dec 1962 |
|
GB |
|
Primary Examiner: Husar; Cornelius J.
Assistant Examiner: Knight; Anthony
Attorney, Agent or Firm: Barnes, Kisselle, Raisch, Choate,
Whittemore & Hulbert
Claims
What I claim is:
1. A quick connect fitting assembly for tubes into which a tube can
be pushed and locked and sealed comprising:
(a) a main fitting body having a utility connection means at one
end and an open-ended cylindrical recess at the other end,
(b) a sleeve piston in said recess in external sealing relating to
said recess and an internal sealing relation to an inserted tube,
said piston having an internal conical recess facing the openend of
said cylindrical recess,
(c) a locking sleeve in said recess in axial alignment with said
piston and having an external conical portion arranged and disposed
to penetrate into said internal conical recess of said piston and
further having a segmental spherical portion with an external
spherical surface opposite said external conical portion,
(d) retainer means engageable with said main fitting body having an
internal spherical surface complemental to and engageable with said
external spherical surface of said locking sleeve, and
(e) wherein said piston, said locking sleeve and said internal and
said external spherical surfaces are arranged and are dimensioned
to provide a swivel joint for limited deviations of said tube from
coaxial alignment with said recess.
2. A quick connect fitting for tubes as defined in claim 1 wherein
said retainer means is a cap and said main fitting body and said
retaining cap have opposed circumferentially extending shoulders to
engage in a snap over connection.
3. A quick connect fitting for tubes as defined in claim 2 in which
said sleeve piston has an annular internal recess at one end and an
annular external recess essentially central of the length of said
sleeve and an O-ring seal in each internal and external recess.
4. A quick connect fitting for tubes as defined in claim 1 in which
said sleeve piston is formed externally as a double frusto-cone
tapering from a large diameter centrally of said piston to a
smaller diameter at the ends.
5. A quick connect fitting for tubes as defined in claim 1 in which
said external conical portion of said locking sleeve is slotted
axially.
6. A quick connect fitting for tubes as defined in claim 1 in which
a locking ring is positioned in said open-ended recess in said main
fitting body between a radial shoulder in said body and the inner
end of said sleeve piston, said ring having an annular internal
edge to lock into the surface of an inserted tube.
7. A quick connect fitting for tubes as defined in claim 6 in which
said radial shoulder in said body is tapered away from the open end
of said body to provide a tapered back-up shoulder for said locking
ring during insertion of a tube into said fitting assembly.
8. A quick connect tube fitting having a main body provided with a
through bore having one end opening outwardly to receive a free end
of the tube when the tube is inserted in a first direction into the
body and means to inhibit withdrawal of the tube in an opposite
direction out of the body including first and second locking means,
said first locking means comprising a locking ring carried in said
bore to receive said free end of the tube when it is inserted in a
first direction into the bore and lock onto said free end and means
for interengaging said lock ring with said fitting body, said
second locking means comprising a sleeve piston and a wedge lock
sleeve carried in said bore in coaxial alignment, said piston
having external sealing means to seal against the body, internal
sealing means to seal on said free end of said tube and first cam
means at an end thereof facing toward said open end that receives
said tube, said wedge lock sleeve having second cam means at one
end facing toward and being generally complementary to said first
cam means on said piston, and wherein said second locking means
further copmrises means interengaging said body with said wedge
lock sleeve so that when said sleeve piston and said wedge lock
sleeve ar axially engaged with each other said wedge lock sleeve is
cammed radially inwardly into locking engagement with said free end
of said tube.
9. The quick connect fitting set forth in claim 8 wherein said
sleeve piston is arranged and disposed in said bore so as to be
axially shiftable in said opposite direction to cam said wedge lock
sleeve into locking engagement with said free end of said tube,
said locking ring is disposed in said bore remote from said open
end thereof and adjacent an end of said sleeve piston opposite the
cam end thereof so that said locking ring after locking onto said
tube is shiftable in said opposite direction into engagement with
said piston to in turn shift said piston in said opposite
direction.
10. The quick connect fitting set forth in claim 9 wherein said
piston is arranged and disposed in said bore so as to be axially
shifted in said opposite direction when said fitting is
pressurized.
11. The quick connect fitting set forth in claim 9 wherein said
locking ring and fitting body interengaging means includes said
piston and said sleeve.
12. The quick connect fitting set forth in claim 8 wherein said
piston is arranged and disposed in said bore so as to be axially
shifted in said opposite direction when said fitting is
pressurized.
13. The quick connect fitting set forth in claim 8 wherein said
wedge lock sleeve and body interengaging means comprises a
spherical surface on said wedge lock sleeve facing generally toward
said open end of said bore and retainer means engageable with said
body and projecting radially inwardly so as to partially close said
open end of said bore, said retainer means having an internal
spherical surface facing generally inwardly of said bore and being
complemental to said spherical surface on said wedge lock
sleeve.
14. The method of quick connecting a tube in a fitting wherein the
fitting has a bore therein open at one end to receive said tube, a
locking ring carried in said bore and sealing and locking means to
seal the space between the bore and a free end of the tube inserted
into the bore in a first direction and to lock the tube in the
bore, said sealing and locking means comprising a piston and a
radially compressible sleeve, said piston and said sleeve having
complementary interengaged camming means to compress the sleeve
into tight engagement with the tube when the piston is shifted in a
direction opposite said first direction, said method comprising the
steps of pushing a free end of the tube into said fitting and
through said sleeve, said piston and said locking ring to lock the
locking ring onto the free end of the tube engaging said locking
ring with said body to inhibit withdrawal of the free end from the
fitting in said opposite direction and then shifting said piston in
said opposite direction to compress said sleeve onto the tube while
interengaging said sleeve and said body so as to achieve a double
locking arrangement of said tube in said fitting.
15. The method set forth in claim 14 wherein said piston is shifted
axially by pulling the tube in said opposite direction to engage
said locking ring with said piston.
16. The method set forth in claim 14 wherein said piston is shifted
axially by pressure against the end thereof when said fitting is
pressurized.
17. The method set forth in claim 14 wherein said piston is shifted
by pressurizing said fitting.
18. A quick connect fitting assembly for tubes into which a tube
can be pushed and locked and sealed comprising:
(a) a main fitting body having a utility connection means at one
end and an open ended cylindrical recess at the other end,
(b) retainer means engageable on said maind body and projecting
radially inwardly of said recess so as to partially close said open
end of said recess and provide an opening through which said tube
can be inserted in a first direction into said recess, said
retainer means having an internal spherical surfcae facing
generally inwardly of said recess,
(c) a sleeve piston in said recess and having an externally mounted
O-ring to seal said piston in said recess and an internally mounted
O-ring to seal said tube in said sleeve when said tube is inserted
through said sleeve piston, said piston further having an internal
camming recess which tapers radially outwardly in a direction
toward said open end of said recess,
(d) a wedge lock sleeve tapered radially inwardly at one end
generally complementary to and in axial alignment with said
outwardly tapered recess of said piston so as to be receivable
within the tapered recess of said piston and cammed radially
inwardly thereby into locking engagement with said tube when said
tube is inserted through said wedge lock sleeve, said wedge sleeve
further having a spherical surface at the other end of said wedge
sleeve complental to said spherical surface on said retainer means
so as to allow for limited swiveling movement of said tube, said
piston and said wedge lock sleeve when said tube is inserted
through said wedge lock sleeve and said piston, and
(e) further locking means in said recess to lock said tube in said
fitting comprising a locking ring arranged and disposed in said
recess so that said tube can be inserted in a first direction
through said ring and said ring locks on said tube and first stop
means in said main body recess to engage said ring to inhibit
withdrawal of said ring and said tube when said tube is urged in a
direction opposite to said first direction.
Description
FIELD OF INVENTION
Connections for tubing wherein the end of a tubing may be pushed
into a threaded connector fitting and securely retained against
withdrawal, thus facilitating a quick connection for tubing into a
position of utility for pneumatic or hydraulic systems.
BACKGROUND OF THE INVENTION
There are many uses for pneumatic or hydraulic tubing in machine
tools, automotive vehicles and numerous other applications. In many
installations, it is desirable to be able to connect the tubing
quickly and effectively. When it is necessary to use wrenches or
other tools to make the connections, much time is lost and tight
joints may not always result unless the involved workman is acting
with skill and care.
In the installation of the tubing in assembly lines, such as tubing
for automotive transmissions, cooling systems and heaters, speed of
installation and quality is essential. it is an object of the
present invention to provide a connector fitting assembly into
which the end of tubing can be inserted and pushed in where it will
instantly be held against withdrawal and sealed against
leakage.
A further object is the provision of a tube fitting which will
allow tube rotation and a limited angular movement without
disturbing the seal and also a structure which will seal more
tightly as pressure increases.
It is a further object to provide a tube fitting for push-in
connection which can be released by proper manipulation of one of
the elements without damage to the tubing.
Other objects of the invention will be apparent in the following
description and claims in which the invention is described together
with details to enable persons skilled in the art to practice the
invention all in connection with the best mode presently
contemplated for the practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Drawings accompany the disclosure and the various views thereof may
be briefly described as:
FIG. 1, a longitudinal section of a connector fitting and tube;
FIG. 2, a side elevation of a locking wedge element of the
fitting;
FIG. 3, an end view of the locking wedge element;
FIG. 4, a side elevation of a body element of the fitting;
FIG. 5, a side elevation of a sleeve piston element of the
fitting;
FIG. 6, a side elevation of an end retainer cap unit for the
fitting;
FIG. 7, an end view of the end cap of FIG. 6.
FIG. 8, a sectional view of the end cap unit.
FIG. 9, a view of an anvil insert for soft tubing.
DETAILED DESCRIPTION OF THE INVENTION AND THE MANNER AND PROCESS OF
USING IT
With reference to the drawings, the assembly drawing in FIGS. 1 and
4 show a body element 20 for the fitting which includes an
externally threaded neck portion 22 having a passage 23, a shoulder
24, a stepped recess 25, and an enlarged portion 26 with a
hexagonal outer surface and a cylindrical inner recess 27. A
shoulder 28 is formed with a 9.degree. taper between recesses 25
and 27. A cylindrical extension 29 enlarges at a shoulder 30 to a
flange which has a chamfer 32 at the end. This body portion 20 may
be formed of metal or a dense plastic.
A snap-on retainer cap 40, FIGS. 1 and 6 to 8, has a body portion
with a tube opening 42 which opens to a spherical recess 44
terminating at its largest diameter in a shoulder 46. The inner
diameter of the shoulder 46 flares outward at 48. Diametrically
opposed notches 50 allow flexing of the periphery of the retainer
cap in assembly and disassembly. This retainer cap 40 is preferably
molded from a plastic material having a form retaining
characteristic but sufficient flexibility to yield for snap-on
assembly and pry-off disassembly.
A third element of the assembly is a locking wedge and sealing
gland 60 illustrated in section in FIG. 1. A side view and an end
view are illustrated respectively in FIGS. 2 and 3. This element 60
has an end portion 62 shaped as a segment of a sphere with a
spherical surface 64 truncated at one end 66 and forming, at its
larger diameter, a shoulder 68 in a plane transverse to the axis of
the part.
From the shoulder 68 a tapered portion 70 extends axially. A tube
passage 72 is formed in the portion 70, this passage tapering
outwardly at 74 at about a 2.degree. angle. The extended portion 70
is provided with four axial slots to allow this portion to squeeze
down on a retainer tube as will be described. This part 62 may also
be molded of plastic.
A fourth element of the assembly is again a molded plastic part
which may be termed a sleeve piston 80 illustrated in section in
FIG. 1 and in elevation in FIG. 5. This part is formed as two
frusto-conical parts 82 back to back and separated by an O-ring
groove 84 for an O-ring 112. The walls of the cones are at about
5.degree. to the axis for the purpose to be explained below. A
cylindrical recess 86 at one end terminates in a shoulder 88 at the
inner end of which originates a tapered recess 90 terminating at
the other end. The recess 86 is provided to receive an O-ring 110
and the tapered recess 90 is provided to complement and receive the
tapered end 70 of part 62. In function, sleeve 80 is formed of a
plastic material which may expand circumferentially when cammed
outwardly by the related tapered portions.
A fifth element of the assembly comprises a closed metallic
retainer ring 100 shown in section in FIG. 1. This ring has an
out-turned lip 102 with a sharp corner 104 which will "grab" the
surface of an inserted tube and prevent withdrawal.
Turning now to the assembly drawing in FIG. 1, the elements 20, 40,
60, 80 and 100 may all be pre-assembled. O-rings 110 and 112 are
pre-assembled on the sleeve piston 80 as shown and the retainer
ring 100 and sleeve piston are moved into the recess 27 of the body
20. The tapered end 70 of the spherically capped locking wedge 60
is then inserted into the tapered recess 90 of the sleeve piston
80. If desired, the part 60 can be pre-assembled into the sleeve
piston 80. The snap-on cap 40 is then pushed onto the body 20 so
that the tapered opening 48 cams over the tapered end 32 and the
shoulders 30 and 46 engage to prevent withdrawal. The parts as
described may be readily assembled by hand.
When the assembled parts are together as viewed in FIG. 1, a tube
120 may be thrust into the opening 72, 74 of the wedge element 60
and through the O-ring 110 in sleeve piston 80. The tube should
have smooth corners to avoid marring the O-ring 110. The tube will
then feed through the hole in the retainer 100 and further
insertion will be blocked by shoulder 24. The inclined shoulder 28
will be contacted by the ring 100 and this will tend to open up the
ring somewhat during the insertion of the tube. Any type of tubing,
metal, plastic, rubber, etc. may be used but it should be free of
sharp edges on the end that is to be inserted and have a reasonably
smooth surface. Once the tube is inserted, it is sealed by O-ring
110 and locked in place by ring 100. During insertion ring 100 may
abut the tapered shoulder 28 as above described. Any withdrawal of
the tube will bring ring 100 into contact with the sleeve piston
which when forced back will cam up on the tapered end 70 of the
capped wedge 60 to tighten the parts and force the complementary
spherical surfaces 44 and 64 into tight contact.
Also, pneumatic or hydraulic pressure will act on the sleeve piston
to tighten the parts in the same manner as a tube pull back. The
slight tapered in opening 74 of the part 60 and the conical shape
of the sleeve piston, as well as the spherical surfaces, allows the
tubing to deviate 5.degree. in any direction for misalignment
stress and vibration absorption in the fitting. In other words,
there is a swivel joint to a limited degree. Also, the O-ring seal
112 is a dynamic seal in the sense that the tube may move angularly
and also the tube may rotate with related parts.
Thus, there is provided a push-in type of connector which
facilitates quick assembly on an assembly line, for example, with
no need for tools. When a tension is applied to the tubing or
internal pressure is present, the glands (sleeve piston 80 and the
O-ring 112 and the part 60) will close around the piston creating a
friction grip on hard tubing and a compression on a soft tubing.
Any pulling or pressure will cause the spherical element 60 to be
tightened around the tube by the spherical surface 62 and the taper
of parts 60 and 80. These forces will also force O-ring 112 against
the wall of recess 27 and move O-ring 110 tighter against the
tube.
When soft tubing is utilized, a stiffener anvil insert 120A, shown
in FIG. 9, is utilized in the end of the tubing prior to insertion
into the connector fitting.
The ring 100 is loose in the assembly prior to the introduction of
the tube, but the tube end will find the opening in the ring and
back it against the tapered shoulder as the tube is pushed through
the ring.
It will be appreciated that the tube, once inserted, cannot be
withdrawn without destroying the locked end. However, the end cap
40 can be removed by spreading the sides opposite the slots 50 to
detach the snap-in shoulders 30, 46 and allow removal. Parts 60 and
80 can then be withdrawn and the lock ring 100 remoed. The tube can
then be reused by installing a new lock ring and proceeding as
before.
* * * * *